I'm investigating the phenolics of black poplar (Populus nigra) and their influence on the insect-plant interactions of this tree species. After characterizing the phenolic profile of black poplar, I performed field studies investigating the seasonal trajectories of phenolics and their response to herbivory. In the second part of my thesis, I'm focusing on the detoxification of salicin-based compounds in the model herbivore Lymantria dispar.